Infrared (IR) thermal imaging has a number of well-established industrial, commercial, and military applications, such as security, law enforcement surveillance and industrial and environmental monitoring. In recent years, however, there has been increasing interest in medical applications for thermal imaging following the continuing improvements in infrared camera technologies.
Thermal imaging is attractive in the medical setting because it is passive, non-invasive, non-ionizing, patient-friendly, and potentially low-cost. Applications of thermal imaging include mapping of skin temperature change induced by trauma, functional imaging of the brain under varying physiological and psychological conditions, imaging of tissue during laparoscopic surgery, treatment of neural and vascular disorders, and, especially, breast cancer detection. Early detection of breast cancer has a major impact on survival rates, and low-cost, highly sensitive IR imaging systems may help to detect small tumors sooner than traditional X-ray mammography.
The successful use of IR imaging relies on the development of more advanced IR imaging systems. Earlier IR cameras using HgCdTe or InSb electro-optic detectors are expensive, bulky, and inconvenient to use because of the need for cryogenic cooling in order to minimize thermal noise. Quantum well IR detectors also require expensive cryogenic or Stirling engine cooling systems to increase their sensitivity. Many of the existing examples of uncooled IR detectors use resistive or piezoresistive readout, and thereby suffer from higher power consumption and thermal resistive noise. Uncooled pyroelectric and ferroelectric IR detectors require choppers to operate, adding complexity to the camera system. Additionally, uncooled thermoelectric IR detectors have low responsivity.
Accordingly, what is needed in the art is an improved IR imaging system and method.